Re: [PATCH v2 3/5] scalar: remove stale config values

From: Junio C Hamano <gitster@pobox.com>
Date: Dec 7, 2025, 00:34 UTC
Message-ID: <xmqqms3vnn9e.fsf@gitster.g>
In-Reply-To: <aS88bnmZXMZCV5oS@pks.im>

Patrick Steinhardt <ps@pks.im> writes:

Show 12 quoted lines

> The logic around this was introduced in 2a9dedef2e (index: make
> index.threads=true enable ieot and eoie, 2018-11-19), and the ultimate
> reason for it seems to be backwards compatibility:
>
>     index.threads and index.recordOffsetTable unspecified: do not write
>     the offset table yet (to avoid alarming the user with "ignoring IEOT
>     extension" messages when an older version of Git accesses the
>     repository) but do make use of multiple threads to read the index if
>     the supporting offset table is present.
>
> Older versions of Git complained when they see unknown extensions, and
> we didn't want to expose users to such warnings.

Not "Older versions".

Any version of Git should complain mandatory index extension that it does not understand. And any version of Git, even today's Git, gives a note when it ignores an optional index extension it does not understand.

> That makes me wonder
> whether it's time now to revisit that decision -- it's been 7 years
> since then, I guess that many clients nowadays would understand the
> extension.

I do not think 7 years matters. The only reason you might see the "ignoring" message is after using a newer version of Git that is aware of that index extension, and then reverting back to an older version. As the index file is a purely local matter, it is not very likely situation to begin with, and when it happens, the user should be made aware of it. Not understanding an optional index extension is not a breaking sin; but being in such a situation, i.e., the user is using older version of Git than they once used to use, is a note worthy vent.

So yes, even this logic was introduced last week, if the only reason is to avoid showing the note, that design decision should be revisited.

Show 5 quoted lines

> The only (documented) downside should thus not be that important
> anymore, but the upside is that reading the index would be faster if we
> default-enable writing the extension.
>
> Patrick